Radiator overflow valve



Patented Feb. 21, 1940 `PATENT rl-"lcE 2,191,636 RADIATOR ovnmow vALvE Nelson Walker, Flint, Mich., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application any s, 193s, semi No. 2116,235

lClaim.

This invention relates to an' improvement in radiator overiiow valves and the structure is intended for application either as original or accessory equipment, to the usual overnow vent pipe of an engine cooling system. It will enable the use oi' more of the available space at the top of the customary automobile radiator shell for housing the upper or inlet tank of the radiator assembly and thereby increase tank capacity. l This is for the reason that pressure valves now in general use are made as a part of the spout closure cap and necessitate a deep spout from which the overiiow pipe leads and the bottom of the spout determines the height of the top tank. Because of the limitation of space and the need for a large tankthe disadvantages of a spout enclosed pressure valve may outweigh its advantages and accordingly it is an object of the present invention to provide for the use oi a large top tank with a relatively short ller spout and a :flatl closure cap with the overiiow leading from the topmost portion ofthe tank and being provided at its discharge end with a pressure valve assembly.

Another object ofthe inventions to provide a low cost unit made from a few easily manufactured parts so related to one another as to insure positive and carefree operation over a long period of time and which may be applied readily to existing cooling systems for their conversion for pressure operation.

A further object of the invention is to provide a valve housing formed of a pair of pressed metal parts joined together to enclose the valve mechanism and wherein one part has a` pressed rib ail'ordng an effective valve seat and the other part has pressed formations affording raised locating and centering seats ior the endmost coil of a valve spring and depressed drain troughs for by-passing the coil spring for the escape of pressure fluid in the event the spring coils close togetherunder the action of internal pressure unseating the valve. To locate and center the opposite end of the valve spring which bears against la backing plate for the sealing gasket constituting the main valve, the backing-plate is provided with struck out tongues at circumierentially spaced points for a nested t with the endmost coil.

A still further object of the invention is to provide a spring seated vacuum relief valve whose stem carries a spring retainer arranged to limit contraction of the spring and thereby prevent closing of the coils andinterference to the now of vacuum relieving iluid.

, Additional objects and advantages of the cont struction will be apparent from the accompanying drawing wherein Figure 1 is a side elevation showing a portion of an engine and its air cooled radiator in the cooling system; Figure 2 shows the upper portion of a more or less conventional type of radiator; Figure 3 is a vertical sectional view of the improved pressure valve and is taken on line 3 3 of Figure 1; Figure 4 is a horizontal sectional view taken on line 4-4 of Figure 3 and Figure 5 is a detail section taken as on line 5--5 o1' Figures.

Referring to the'drawing, the numeral l in-l dicates the radiator core forming a part of the `circulating cooling system having the inlet tank 2 -at its upper end which is provided with a illler spout 3 closed by a removable cap' I. From the uppermost portion of the tank leads an overow or vent pipe 5 extending down the side oi the radiator according to usual practice. To the lower end of the pipe 5 may be connected by a suitable coupling hose 6 the tubular end er inlet 'i of the valve mechanism which controls the overow.

The valve mechanism is enclosed within a vhousing comprising the casing il and the cover S secured together by iiangngv or peening the adjacent ends together as at l0. These parts, as wellas the valve parts, may be stamped from brass or other metal which resists corrosion. The casing 8 is a cupped pressing having in the base thereof the alternately arranged depressions or troughs l2 and ribs i3. The bottom wall of the stamping 8 also has a central opening formed by the tubular extension i4 and into which the depressed troughs I2 enter. For some installations the extension I4 can vbe omitted and discharge openings provided in the wall of the casing 8 but for uniformity of product it will be better to construct the parts as shown, inasmuch as it may be desirable under certain conditions to install the valve unit intermediate the ends of the overow pipe 5, as for example, near the upper end oi the pipe in which case a section of the pipe would be kcut away and the remaining ends coupled to the opposite end extensions l and I4.

' Each of the radial ribs I3 has a shouldered portion l5 yandthe several shoulders cooperate with one another to form a locating and centering seat for the lowermost coil of the main valve seating spring I6 as seen in Figure 3, so that the spring is located Wholly above the bottoms of the several drain troughs I2. 'I'he opposite end oi the spring I6 bearing against the backing plate I1 is centered by downwardly struck tongues I8-fitted to the coils so that lateral displacement of the valve assembly is unlikely to occur. A gasket or disk I9 of Duprene or similar material is carried by the backing plate to engage the annular rib 26 pressed in the cover 9. To afford a tight seal the surface of the rib 20 engaged by the gasket should be worked smooth. e

The gasket and backing plate are secured together by a hollow rivet or eyelet 2| extending through aligned openings in the center of the parts and the eyelet is closed by a gasket or ring 22 also formed of Duprene and which is mounted on the headed stud or pin 23 extending through the opening in the main valve. The gasket 22 is seated by a light spring 28 bearing on the underside of the backing plate II vat one end.-v and at its opposite end against a cupped retainer 25 carried by the lower end of the pin 23. the attachment being made by forming the end of the pin as a hollow rivet and peening it over the retainer. The side wall of the retainer is cut away at spaced intervals aording a series of projecting iingers 26 which bottom against the underside of the backing plate I'I to prevent the coils of the spring 24 closing together, thereby insuring free passage of uid when the gasket 22 is un seated.

At its margin the backing plate I'l is provided with a dependent stiffening ange 21 which is spaced from the wall of the casing 8 to afford a free path for the escape of pressure fluid. It is desirable, however, to guard against excessive lateral displacement of the valve relative to its seat by arranging projecting portions of the backing plate at circumferentially spaced intervals to approach closely the circular wall of the casing 8. By way of example this is illustrated In this fully opened posiy interfere with the discharge of pressure uid, inasmuch as the depressed troughs I2 provide a by-pass around the compressed spring.

In the assembly of the parts after their formationthe elements of the valveare first brought j together and then introduced together with the spring I6 into the casing 8. Thereupon the cover 9 is brought into closing relation with the casing 8 and its rim spun over to eiect the joint I0. The unit assembly thus formed may be readily applied to the customary overiow pipe Where- Vuponl the cooling system will be closed for pressure operation. To prevent bursting of the parts and leakage at the pump packings and hose connections the resistance of the main spring IB is selected so that the valve will open -at three or four pounds pressure. Thus the systemoperates normally under an internal pressure which increases the eiiiciency of vthe cooling system. Excess pressure is relieved and the discharged pressure iiuid escapes from the overflow pipe 5.

after passing through the valve unit. To prevent strain on the parts after the system cools down, in the event the contraction of the system contents causes an internal depression, the gasket 22 will open against the light spring 24 for the bleeding into ^the system of air until pressures are substantially equalized. As will be apparent, the location of the pressure valve in ,the overflow pipe will enable use of all the available height within the upper portion of the radiator shell to be occupied by the inlet tank so that maximum tank capacity is aorded.

I claim Y In a radiator overiiow valve, a casing, a valve within the casing comprising `a. gasket and a backing plate therefor, a hollow rivet securing together the gasket and backing plate, a second gasket seating over and having a pin projecting through the hollow rivet, a coil spring to seat the last mentioned rivet and bearing at one end on said plate and a spring retainer carried by the pin to seat the opposite end of the spring and provided with plate engaging stops to limit compression of the spring and prevent closing of its coils.

NELSON WALKER. 

